Home > Archive > Cobol > June 2004 > Re: IBM 1401 was: Re: Is it possible to use the value of the PROGRAM ID within the so
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Re: IBM 1401 was: Re: Is it possible to use the value of the PROGRAM ID within the so
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| Tom Morrison 2004-06-14, 3:55 pm |
| "Clark F. Morris, Jr." <cfmtech@istar.ca> wrote in message
news:cag4bh$j8c$1@news.eusc.inter.net...
[snip]
> Emulation on Intel would be interesting. It probably would be slow.
It all depends on what your definition of 'slow' is.
My first computer programming job (outside of college) was translating 1401
Autocoder to this new-fangled 360 COBOL. This was done for a large
manufacturing concern that literally had acres (hectares) of 360s, including
row upon row of 360/30s running in 1401 emulation mode. Of course they
were faster than the 1401s they replaced.
There is absolutely no doubt in my mind that the 2.8GHz Intel waiting for me
to type this could emulate several 1401s between keystrokes, and still
perform better than the original 1401 speed!
Tom Morrison
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| Chuck Stevens 2004-06-14, 3:55 pm |
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"Clark F. Morris, Jr." <cfmtech@istar.ca> wrote in message
news:cag4bh$j8c$1@news.eusc.inter.net...
> I remember the 1401. It had characters with six bits plus a word mark
> bit. All fields were terminated by a word mark, a record mark or a
> group mark. I forget whether the group mark was a record mark with the
> word mark bit set or a record mark was a group mark with the word mark
> bit set. The 1401/1440 definitely could not handle the 2002 standard
> with only three character addresses maximum and I doubt the big brothers
> 1410/7010 would have been equal to the task. With all fields being
> variable, the series was not well suited to COBOL with multiple record
> formats. Many of the instructions were variable length of 1, 4 or 7
> characters. The Move Instruction M meant Move A to B stopping at the
> word mark. If an address was omitted it meant pick up where the
> previous instruction left off. All told an intriguing machine.
I maintain that *given enough time* you could do anything on a 1401. It
might not be easy. It might not be straightforward. But presuming the task
at hand did not require peripherals unavailable on a 1401 it is *doable* if
you're willing to wait long enough.
I remember writing a model of the chemical reactions in the human retina
(which involved five simultaneous linear differential equations with
coefficients too great to allow for Runge-Kutta techniques, requiring a
Laplace transform which had to be solved for the quartic and thence to the
binomials using Newton-Raphson iterations) on, first, an Interdata Model 3
(which had no hardware multiply/divide, much less floating-point hardware),
and subsequently on a Wang 700 programmable calculator using code
segmentation and automatic loading on the program cassette drive.
While the Wang took a few hours to do a "run", and the Interdata took three
days, two hours, and ten minutes, the same equation could be solved in a few
minutes on the Philco 2000/210.
I didn't say the 1401 would execute 2002 COBOL code *rapidly*
> Emulation on the Intel would be interesting. It probably would be slow.
Actually, I doubt it!
-Chuck Stevens
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| Robert Wagner 2004-06-15, 3:55 am |
| "Chuck Stevens" <charles.stevens@unisys.com> wrote:
>"Clark F. Morris, Jr." <cfmtech@istar.ca> wrote in message
>news:cag4bh$j8c$1@news.eusc.inter.net...
>
>I maintain that *given enough time* you could do anything on a 1401. It
>might not be easy. It might not be straightforward. But presuming the task
>at hand did not require peripherals unavailable on a 1401 it is *doable* if
>you're willing to wait long enough.
I maintain a machine needs only one instruction to solve any problem. There
wouldn't be an opcode. The four operands would be o1 and o2, the source and
destination for a (possibly indexed) copy; o3, the object of a test; and o4, the
address and condition of a call.
Let's call this hypothetical machine CADET, for Can't Add, Doesn't Even Try. It
could do arithmetic by table lookup using two indicies. The RCA 301 actually
worked that way. If someone stepped on the arithmetic table at a fixed address
in low memory, answers came out wrong until you rebooted the machine.
>I remember writing a model of the chemical reactions in the human retina
>(which involved five simultaneous linear differential equations with
>coefficients too great to allow for Runge-Kutta techniques,
Adams-Moulton techniques would likely have handled the range.
>requiring a
>Laplace transform which had to be solved for the quartic and thence to the
>binomials using Newton-Raphson iterations)
Birge-Vieta methods of pivotal condensation would have speeded up that phase.
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